This invention relates generally to medical diagnostic instruments, and has particular reference to a novel audiometer that is incorporated in a hand held otoscope.
Hand held otoscopes of both the diagnostic and operating types are well known in the prior art. Likewise, audiometers for detecting hearing disabilities are well known. Conventional audiometers are not hand held instruments but rather are relatively large table supported units that utilize earphones in testing the patient. In addition, conventional audiometer equipment is usually installed in sound proof cells or the like so that ambient noise is reduced to a minimum.
The only easily portable, hand held audiometer known to the applicant is disclosed in U.S. Pat. No. 3,105,876, issued Oct. 1, 1963 to C. D. Mullin et al. The Mullin apparatus is not a combination instrument as is the present invention and is capable of operating only as a hearing checking device. The Mullin audiometer checks the hearing capabilities of the patient at a plurality of frequency and intensity levels. Unfortunately, the frequencies are changed by manually moving a dial and this in itself creates a noise that can give the patient a clue or a miscue. Another drawback of the Mullin apparatus is that the duration of the audio-frequency signal is apparently under the control of the operator whereas the duration of the signals should be completely uniform and precise for accurate test results.